Bug 1662840: Move `overrideDPPX` from nsIContentViewer to BrowsingContext. r=whimboo,remote-protocol-reviewers,mtigley,emilio

Differential Revision: https://phabricator.services.mozilla.com/D104001

devtools/client/responsive/test/browser/browser_tab_remoteness_change_fission_switch_target.js

@@ -35,16 +35,7 @@ add_task(async function() {
 
 async function assertDocshell(tab, expectedRDMMode, expectedDPPX) {
   await asyncWaitUntil(async () => {
-    const { overrideDPPX, inRDMPane } = await SpecialPowers.spawn(
-      tab.linkedBrowser,
-      [],
-      () => {
-        return {
-          overrideDPPX: content.docShell.contentViewer.overrideDPPX,
-          inRDMPane: content.docShell.browsingContext.inRDMPane,
-        };
-      }
-    );
+    const { overrideDPPX, inRDMPane } = tab.linkedBrowser.browsingContext;
     return inRDMPane === expectedRDMMode && overrideDPPX === expectedDPPX;
   });
   ok(true, "The state of the docshell is correct");

devtools/server/actors/accessibility/walker.js

@@ -1072,19 +1072,7 @@ const AccessibleWalkerActor = ActorClassWithSpec(accessibleWalkerSpec, {
    * highlighter features correctly.
    */
   get pixelRatio() {
-    const { contentViewer } = this.targetActor.docShell;
-    const { windowUtils } = this.rootWin;
-    const overrideDPPX = contentViewer.overrideDPPX;
-    let ratio;
-    if (overrideDPPX) {
-      contentViewer.overrideDPPX = 0;
-      ratio = windowUtils.screenPixelsPerCSSPixel;
-      contentViewer.overrideDPPX = overrideDPPX;
-    } else {
-      ratio = windowUtils.screenPixelsPerCSSPixel;
-    }
-
-    return ratio;
+    return this.rootWin.windowUtils.screenPixelsPerCSSPixelNoOverride;
   },
 
   /**

devtools/server/actors/emulation/responsive.js

@@ -104,13 +104,14 @@ const ResponsiveActor = protocol.ActorClassWithSpec(responsiveSpec, {
       this._previousDPPXOverride = this.getDPPXOverride();
     }
 
-    this.docShell.contentViewer.overrideDPPX = dppx;
+    // FIXME: This should be set in the parent process.
+    this.docShell.browsingContext.overrideDPPX = dppx;
 
     return true;
   },
 
   getDPPXOverride() {
-    return this.docShell.contentViewer.overrideDPPX;
+    return this.docShell.browsingContext.overrideDPPX;
   },
 
   clearDPPXOverride() {

docshell/base/BrowsingContext.cpp

@@ -185,6 +185,14 @@ BrowsingContext* BrowsingContext::Top() {
   return bc;
 }
 
+const BrowsingContext* BrowsingContext::Top() const {
+  const BrowsingContext* bc = this;
+  while (bc->mParentWindow) {
+    bc = bc->GetParent();
+  }
+  return bc;
+}
+
 int32_t BrowsingContext::IndexOf(BrowsingContext* aChild) {
   int32_t index = -1;
   for (BrowsingContext* child : Children()) {
@@ -2567,6 +2575,28 @@ void BrowsingContext::DidSet(FieldIndex<IDX_Muted>) {
   });
 }
 
+bool BrowsingContext::CanSet(FieldIndex<IDX_OverrideDPPX>, const float& aValue,
+                             ContentParent* aSource) {
+  // FIXME: Should only be settable by the parent process, but devtools code
+  // currently sets it from the child.
+  return IsTop() && LegacyCheckOnlyOwningProcessCanSet(aSource);
+}
+
+void BrowsingContext::DidSet(FieldIndex<IDX_OverrideDPPX>, float aOldValue) {
+  MOZ_ASSERT(IsTop());
+  if (GetOverrideDPPX() == aOldValue) {
+    return;
+  }
+
+  PreOrderWalk([&](BrowsingContext* aContext) {
+    if (nsIDocShell* shell = aContext->GetDocShell()) {
+      if (nsPresContext* pc = shell->GetPresContext()) {
+        pc->RecomputeBrowsingContextDependentData();
+      }
+    }
+  });
+}
+
 void BrowsingContext::SetCustomUserAgent(const nsAString& aUserAgent,
                                          ErrorResult& aRv) {
   Top()->SetUserAgentOverride(aUserAgent, aRv);

docshell/base/BrowsingContext.h

@@ -169,6 +169,7 @@ enum class ExplicitActiveStatus : uint8_t {
   FIELD(FullZoom, float)                                                      \
   FIELD(WatchedByDevToolsInternal, bool)                                      \
   FIELD(TextZoom, float)                                                      \
+  FIELD(OverrideDPPX, float)                                                  \
   /* The current in-progress load. */                                         \
   FIELD(CurrentLoadIdentifier, Maybe<uint64_t>)                               \
   /* See nsIRequest for possible flags. */                                    \
@@ -389,6 +390,7 @@ class BrowsingContext : public nsILoadContext, public nsWrapperCache {
 
   BrowsingContext* GetParent() const;
   BrowsingContext* Top();
+  const BrowsingContext* Top() const;
   int32_t IndexOf(BrowsingContext* aChild);
 
   // NOTE: Unlike `GetEmbedderWindowGlobal`, `GetParentWindowContext` does not
@@ -490,6 +492,8 @@ class BrowsingContext : public nsILoadContext, public nsWrapperCache {
   float FullZoom() const { return GetFullZoom(); }
   float TextZoom() const { return GetTextZoom(); }
 
+  float OverrideDPPX() const { return Top()->GetOverrideDPPX(); }
+
   bool SuspendMediaWhenInactive() const {
     return GetSuspendMediaWhenInactive();
   }
@@ -936,6 +940,10 @@ class BrowsingContext : public nsILoadContext, public nsWrapperCache {
   // volume of all media elements.
   void DidSet(FieldIndex<IDX_Muted>);
 
+  bool CanSet(FieldIndex<IDX_OverrideDPPX>, const float& aValue,
+              ContentParent* aSource);
+  void DidSet(FieldIndex<IDX_OverrideDPPX>, float aOldValue);
+
   bool CanSet(FieldIndex<IDX_EmbedderInnerWindowId>, const uint64_t& aValue,
               ContentParent* aSource);
 

docshell/base/nsDocShell.cpp

@@ -7373,14 +7373,6 @@ nsresult nsDocShell::RestoreFromHistory() {
     mSavingOldViewer = CanSavePresentation(mLoadType, request, doc);
   }
 
-  nsCOMPtr<nsIContentViewer> oldCv(mContentViewer);
-  nsCOMPtr<nsIContentViewer> newCv(viewer);
-  float overrideDPPX = 0.0f;
-
-  if (oldCv) {
-    oldCv->GetOverrideDPPX(&overrideDPPX);
-  }
-
   // Protect against mLSHE going away via a load triggered from
   // pagehide or unload.
   nsCOMPtr<nsISHEntry> origLSHE = mLSHE;
@@ -7603,10 +7595,6 @@ nsresult nsDocShell::RestoreFromHistory() {
     FavorPerformanceHint(true);
   }
 
-  if (oldCv) {
-    newCv->SetOverrideDPPX(overrideDPPX);
-  }
-
   if (document) {
     RefPtr<nsDocShell> parent = GetInProcessParentDocshell();
     if (parent) {
@@ -8173,7 +8161,6 @@ nsresult nsDocShell::SetupNewViewer(nsIContentViewer* aNewViewer,
 
   const Encoding* hintCharset = nullptr;
   int32_t hintCharsetSource = kCharsetUninitialized;
-  float overrideDPPX = 1.0;
   // |newMUDV| also serves as a flag to set the data from the above vars
   nsCOMPtr<nsIContentViewer> newCv;
 
@@ -8205,8 +8192,6 @@ nsresult nsDocShell::SetupNewViewer(nsIContentViewer* aNewViewer,
         hintCharset = oldCv->GetHintCharset();
         NS_ENSURE_SUCCESS(oldCv->GetHintCharacterSetSource(&hintCharsetSource),
                           NS_ERROR_FAILURE);
-        NS_ENSURE_SUCCESS(oldCv->GetOverrideDPPX(&overrideDPPX),
-                          NS_ERROR_FAILURE);
       }
     }
   }
@@ -8263,9 +8248,10 @@ nsresult nsDocShell::SetupNewViewer(nsIContentViewer* aNewViewer,
     newCv->SetHintCharset(hintCharset);
     NS_ENSURE_SUCCESS(newCv->SetHintCharacterSetSource(hintCharsetSource),
                       NS_ERROR_FAILURE);
-    NS_ENSURE_SUCCESS(newCv->SetOverrideDPPX(overrideDPPX), NS_ERROR_FAILURE);
   }
 
+  NS_ENSURE_TRUE(mContentViewer, NS_ERROR_FAILURE);
+
   // Stuff the bgcolor from the old pres shell into the new
   // pres shell. This improves page load continuity.
   if (RefPtr<PresShell> presShell = mContentViewer->GetPresShell()) {

docshell/base/nsIContentViewer.idl

@@ -257,13 +257,6 @@ interface nsIContentViewer : nsISupports
    */
   readonly attribute float deviceFullZoomForTest;
 
-  /**
-   * The value used to override devicePixelRatio and media queries dppx.
-   * Default is 0.0, that means no overriding is done (only a positive value
-   * is applied).
-   */
-  attribute float overrideDPPX;
-
   /**
    * Disable entire author style level (including HTML presentation hints),
    * for this viewer but not any child viewers.

dom/base/Document.cpp

@@ -890,18 +890,6 @@ void ExternalResourceMap::ShowViewers() {
   }
 }
 
-void TransferOverrideDPPX(Document* aFromDoc, Document* aToDoc) {
-  MOZ_ASSERT(aFromDoc && aToDoc, "transferring zoom levels from/to null doc");
-
-  nsPresContext* fromCtxt = aFromDoc->GetPresContext();
-  if (!fromCtxt) return;
-
-  nsPresContext* toCtxt = aToDoc->GetPresContext();
-  if (!toCtxt) return;
-
-  toCtxt->SetOverrideDPPX(fromCtxt->GetOverrideDPPX());
-}
-
 void TransferShowingState(Document* aFromDoc, Document* aToDoc) {
   MOZ_ASSERT(aFromDoc && aToDoc, "transferring showing state from/to null doc");
 
@@ -955,7 +943,6 @@ nsresult ExternalResourceMap::AddExternalResource(nsIURI* aURI,
     if (nsPresContext* pc = doc->GetPresContext()) {
       pc->RecomputeBrowsingContextDependentData();
     }
-    TransferOverrideDPPX(aDisplayDocument, doc);
     TransferShowingState(aDisplayDocument, doc);
   }
 

dom/chrome-webidl/BrowsingContext.webidl

@@ -129,6 +129,13 @@ interface BrowsingContext {
 
   [SetterThrows] attribute float textZoom;
 
+  // Override the dots-per-CSS-pixel scaling factor in this BrowsingContext
+  // and all of its descendants. May only be set on the top BC, and should
+  // only be set from the parent process.
+  //
+  // A value of 0.0 causes us to use the global default scaling factor.
+  [SetterThrows] attribute float overrideDPPX;
+
   [SetterThrows] attribute boolean suspendMediaWhenInactive;
 
   // Default value for nsIContentViewer::authorStyleDisabled in any new

dom/tests/mochitest/general/test_contentViewer_overrideDPPX.html

@@ -42,8 +42,10 @@ const setOverrideDPPX = (value) => {
     info(`restore window's dppx to default value`);
   }
 
-  SpecialPowers.setOverrideDPPX(window, value);
-}
+  return SpecialPowers.spawnChrome([value], dppx => {
+    browsingContext.top.overrideDPPX = dppx;
+  });
+};
 
 const setFullZoom = (value) => {
   info(`set window's fullZoom to ${value}`);
@@ -95,17 +97,17 @@ const waitForMediaQueryListEvent = (mediaQueryList) => {
 }
 
 const gTests = {
-  "test overrideDPPX with devicePixelRatio": (done) => {
+  "test overrideDPPX with devicePixelRatio": async (done) => {
     assertValuesAreInitial();
 
-    setOverrideDPPX(dppx);
+    await setOverrideDPPX(dppx);
 
     is(window.devicePixelRatio, dppx,
       "devicePixelRatio overridden.");
     is(frameWindow.devicePixelRatio, dppx,
       "frame's devicePixelRatio overridden.");
 
-    setOverrideDPPX(0);
+    await setOverrideDPPX(0);
 
     is(window.devicePixelRatio, originalDPR,
       "devicePixelRatio back to default.");
@@ -114,18 +116,18 @@ const gTests = {
 
     done();
   },
-  "test overrideDPPX with devicePixelRatio and fullZoom": (done) => {
+  "test overrideDPPX with devicePixelRatio and fullZoom": async (done) => {
     assertValuesAreInitial();
 
     setFullZoom(zoom);
-    setOverrideDPPX(dppx);
+    await setOverrideDPPX(dppx);
 
     is(window.devicePixelRatio, dppx,
       "devicePixelRatio overridden; fullZoom ignored");
     is(frameWindow.devicePixelRatio, dppx,
       "frame's devicePixelRatio overridden; fullZoom ignored");
 
-    setOverrideDPPX(0);
+    await setOverrideDPPX(0);
 
     is(window.devicePixelRatio, originalDPR * zoom,
       "devicePixelRatio now is affected by fullZoom");
@@ -144,7 +146,7 @@ const gTests = {
     done();
 
   },
-  "test overrideDPPX with media queries": (done) => {
+  "test overrideDPPX with media queries": async (done) => {
     assertValuesAreInitial();
 
     let frameDoc = frameWindow.document;
@@ -163,7 +165,7 @@ const gTests = {
     is(frameCurrentFontSize, frameOriginalFontSize,
       "frame's media queries are not applied yet");
 
-    setOverrideDPPX(dppx);
+    await setOverrideDPPX(dppx);
 
     currentFontSize = getBodyFontSize(window);
     frameCurrentFontSize = getBodyFontSize(frameWindow);
@@ -178,7 +180,7 @@ const gTests = {
     is(frameCurrentFontSize, "32px",
       "frame's font size has the expected value.");
 
-    setOverrideDPPX(0);
+    await setOverrideDPPX(0);
 
     currentFontSize = getBodyFontSize(window);
     frameCurrentFontSize = getBodyFontSize(frameWindow);
@@ -193,7 +195,7 @@ const gTests = {
 
     done();
   },
-  "test overrideDPPX with media queries and fullZoom": (done) => {
+  "test overrideDPPX with media queries and fullZoom": async (done) => {
     assertValuesAreInitial();
 
     let frameDoc = frameWindow.document;
@@ -215,7 +217,7 @@ const gTests = {
       "frame's media queries are not applied yet");
 
     setFullZoom(zoom);
-    setOverrideDPPX(dppx);
+    await setOverrideDPPX(dppx);
 
     currentFontSize = getBodyFontSize(window);
     frameCurrentFontSize = getBodyFontSize(frameWindow);
@@ -224,7 +226,7 @@ const gTests = {
     is(frameCurrentFontSize, "32px",
       "frame's media queries are applied for overridden DDPX; fullZoom ignored.");
 
-    setOverrideDPPX(0);
+    await setOverrideDPPX(0);
 
     currentFontSize = getBodyFontSize(window);
     frameCurrentFontSize = getBodyFontSize(frameWindow);
@@ -262,7 +264,7 @@ const gTests = {
 
     setOverrideDPPX(dppx);
   },
-  "test OverrideDPPX with MediaQueryList and fullZoom": (done) => {
+  "test OverrideDPPX with MediaQueryList and fullZoom": async (done) => {
     assertValuesAreInitial();
 
     let promises = [
@@ -272,7 +274,7 @@ const gTests = {
         window.matchMedia(`(resolution: ${originalDPR * zoom}dppx)`)),
     ];
 
-    setOverrideDPPX(dppx);
+    await setOverrideDPPX(dppx);
     setFullZoom(zoom);
 
     promises[0]
@@ -281,7 +283,7 @@ const gTests = {
       .then(() => setFullZoom(originalZoom))
       .then(done, e => {throw e});
   },
-  "test OverrideDPPX is kept on document navigation": (done) => {
+  "test OverrideDPPX is kept on document navigation": async (done) => {
     assertValuesAreInitial();
 
     let frameOriginalFontSize = getBodyFontSize(frameWindow);
@@ -291,7 +293,7 @@ const gTests = {
     is(frameCurrentFontSize, frameOriginalFontSize,
       "frame's media queries are not applied yet");
 
-    setOverrideDPPX(dppx);
+    await setOverrideDPPX(dppx);
 
     frameCurrentFontSize = getBodyFontSize(frameWindow);
 
@@ -302,7 +304,7 @@ const gTests = {
     is(frameCurrentFontSize, "32px",
       "frame's font size has the expected value.");
 
-    frameWindow.frameElement.addEventListener("load", function() {
+    frameWindow.frameElement.addEventListener("load", async function() {
       frameStyle = createFontStyleForDPPX(frameWindow.document, dppx, "32");
 
       frameCurrentFontSize = getBodyFontSize(frameWindow);
@@ -316,7 +318,7 @@ const gTests = {
 
       frameStyle.remove();
 
-      setOverrideDPPX(0);
+      await setOverrideDPPX(0);
 
       done();
     }, {once: true});
@@ -343,28 +345,28 @@ const gTests = {
     // so that the first override will always trigger a load.
     isnot(originalDPR, 8, "originalDPR differs from final test value");
     loaded = new Promise(resolve => image.onload = resolve);
-    setOverrideDPPX(8);
+    await setOverrideDPPX(8);
     await loaded;
 
     is(image.currentSrc, imageSets["8x"],
       "Image is properly set for 8dppx.");
 
     loaded = new Promise(resolve => image.onload = resolve);
-    setOverrideDPPX(1);
+    await setOverrideDPPX(1);
     await loaded;
 
     is(image.currentSrc, imageSets["1x"],
       "Image url is properly set for 1dppx.");
 
     loaded = new Promise(resolve => image.onload = resolve);
-    setOverrideDPPX(1.5);
+    await setOverrideDPPX(1.5);
     await loaded;
 
     is(image.currentSrc, imageSets["1.5x"],
       "Image url is properly set for 1.5dppx.");
 
     loaded = new Promise(resolve => image.onload = resolve);
-    setOverrideDPPX(2);
+    await setOverrideDPPX(2);
     await loaded;
 
     is(image.currentSrc, imageSets["2x"],
@@ -374,14 +376,14 @@ const gTests = {
     // so that resetting to the default will always trigger a load.
     isnot(originalDPR, 8, "originalDPR differs from final test value");
     loaded = new Promise(resolve => image.onload = resolve);
-    setOverrideDPPX(8);
+    await setOverrideDPPX(8);
     await loaded;
 
     is(image.currentSrc, imageSets["8x"],
       "Image is properly set for 8dppx.");
 
     loaded = new Promise(resolve => image.onload = resolve);
-    setOverrideDPPX(0);
+    await setOverrideDPPX(0);
     await loaded;
 
     is(image.currentSrc, originalSrc,

layout/base/nsDocumentViewer.cpp

@@ -459,8 +459,6 @@ class nsDocumentViewer final : public nsIContentViewer,
 
   nsIntRect mBounds;
 
-  float mOverrideDPPX;  // DPPX overrided, defaults to 0.0
-
   int16_t mNumURLStarts;
   int16_t mDestroyBlockedCount;
 
@@ -537,7 +535,6 @@ void nsDocumentViewer::PrepareToStartLoad() {
 nsDocumentViewer::nsDocumentViewer()
     : mParentWidget(nullptr),
       mAttachedToParent(false),
-      mOverrideDPPX(0.0),
       mNumURLStarts(0),
       mDestroyBlockedCount(0),
       mStopped(false),
@@ -758,7 +755,6 @@ nsresult nsDocumentViewer::InitPresentationStuff(bool aDoInitialReflow) {
     mPresContext->SetVisibleArea(nsRect(0, 0, width, height));
     // We rely on the default zoom not being initialized until here.
     mPresContext->RecomputeBrowsingContextDependentData();
-    mPresContext->SetOverrideDPPX(mOverrideDPPX);
   }
 
   if (mWindow && mDocument->IsTopLevelContentDocument()) {
@@ -2610,34 +2606,6 @@ nsDocumentViewer::GetDeviceFullZoomForTest(float* aDeviceFullZoom) {
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsDocumentViewer::SetOverrideDPPX(float aDPPX) {
-  // If we don't have a document, then we need to bail.
-  if (!mDocument) {
-    return NS_ERROR_FAILURE;
-  }
-
-  mOverrideDPPX = aDPPX;
-
-  auto childFn = [aDPPX](nsDocumentViewer* aChild) {
-    aChild->SetOverrideDPPX(aDPPX);
-  };
-  auto presContextFn = [aDPPX](nsPresContext* aPc) {
-    aPc->SetOverrideDPPX(aDPPX);
-  };
-  PropagateToPresContextsHelper(childFn, presContextFn);
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-nsDocumentViewer::GetOverrideDPPX(float* aDPPX) {
-  NS_ENSURE_ARG_POINTER(aDPPX);
-
-  nsPresContext* pc = GetPresContext();
-  *aDPPX = pc ? pc->GetOverrideDPPX() : mOverrideDPPX;
-  return NS_OK;
-}
-
 NS_IMETHODIMP
 nsDocumentViewer::SetAuthorStyleDisabled(bool aStyleDisabled) {
   if (mPresShell) {

layout/base/nsPresContext.cpp

@@ -773,6 +773,7 @@ void nsPresContext::RecomputeBrowsingContextDependentData() {
   }
   SetFullZoom(browsingContext->FullZoom());
   SetTextZoom(browsingContext->TextZoom());
+  SetOverrideDPPX(browsingContext->OverrideDPPX());
   if (doc == mDocument) {
     // Medium doesn't apply to resource documents, etc.
     auto* top = browsingContext->Top();

layout/base/nsPresContext.h

@@ -531,6 +531,7 @@ class nsPresContext : public nsISupports, public mozilla::SupportsWeakPtr {
     UpdateEffectiveTextZoom();
   }
   void SetFullZoom(float aZoom);
+  void SetOverrideDPPX(float);
 
  public:
   float GetFullZoom() { return mFullZoom; }
@@ -542,7 +543,6 @@ class nsPresContext : public nsISupports, public mozilla::SupportsWeakPtr {
   float GetDeviceFullZoom();
 
   float GetOverrideDPPX() const { return mMediaEmulationData.mDPPX; }
-  void SetOverrideDPPX(float);
 
   /**
    * Recomputes the data dependent on the browsing context, like zoom and text

remote/domains/content/Emulation.jsm

@@ -37,8 +37,4 @@ class Emulation extends ContentProcessDomain {
       });
     });
   }
-
-  _setDPPXOverride(dppx) {
-    this.docShell.contentViewer.overrideDPPX = dppx;
-  }
 }

remote/domains/parent/Emulation.jsm

@@ -69,7 +69,8 @@ class Emulation extends Domain {
     const { tab } = this.session.target;
     const { linkedBrowser: browser } = tab;
 
-    await this.executeInChild("_setDPPXOverride", deviceScaleFactor);
+    const { browsingContext } = this.session.target;
+    browsingContext.overrideDPPX = deviceScaleFactor;
 
     // With a value of 0 the current size is used
     const { layoutViewport } = await this.session.execute(

remote/test/browser/page/browser_captureScreenshot.js

@@ -506,10 +506,7 @@ async function getDevicePixelRatio() {
 }
 
 async function setDevicePixelRatio(dppx) {
-  await SpecialPowers.spawn(gBrowser.selectedBrowser, [dppx], function(dppx) {
-    content.docShell.contentViewer.overrideDPPX = dppx;
-    is(content.devicePixelRatio, dppx, "devicePixelRatio override set");
-  });
+  gBrowser.selectedBrowser.browsingContext.overrideDPPX = dppx;
 }
 
 async function getImageDetails(image) {

testing/specialpowers/content/SpecialPowersChild.jsm

@@ -1182,13 +1182,6 @@ class SpecialPowersChild extends JSWindowActorChild {
     BrowsingContext.getFromWindow(window).textZoom = zoom;
   }
 
-  getOverrideDPPX(window) {
-    return this._getMUDV(window).overrideDPPX;
-  }
-  setOverrideDPPX(window, dppx) {
-    this._getMUDV(window).overrideDPPX = dppx;
-  }
-
   emulateMedium(window, mediaType) {
     BrowsingContext.getFromWindow(window).top.mediumOverride = mediaType;
   }