Bug 1766308 - Add gfxVars::CodecSupportInfo to store user-readable codec support string r=media-playback-reviewers,alwu

Differential Revision: https://phabricator.services.mozilla.com/D147386

gfx/config/gfxVars.h

@@ -84,6 +84,7 @@ class gfxVarReceiver;
   _(UseEGL, bool, false)                                           \
   _(DrmRenderDevice, nsCString, nsCString())                       \
   _(UseDMABuf, bool, false)                                        \
+  _(CodecSupportInfo, nsCString, nsCString())                      \
   _(WebRenderRequiresHardwareDriver, bool, false)                  \
   _(SupportsThreadsafeGL, bool, false)                             \
   _(OffscreenCanvasDomainAllowlist, nsCString, nsCString())        \

gfx/tests/gtest/TestConfigManager.cpp

@@ -154,6 +154,9 @@ class MockGfxInfo final : public nsIGfxInfo {
   NS_IMETHOD GetTargetFrameRate(uint32_t* aTargetFrameRate) override {
     return NS_ERROR_NOT_IMPLEMENTED;
   }
+  NS_IMETHOD GetCodecSupportInfo(nsACString& aCodecSupportInfo) override {
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
   NS_IMETHOD GetD2DEnabled(bool* aD2DEnabled) override {
     return NS_ERROR_NOT_IMPLEMENTED;
   }

widget/GfxInfoBase.cpp

@@ -1865,6 +1865,12 @@ GfxInfoBase::GetTargetFrameRate(uint32_t* aTargetFrameRate) {
   return NS_OK;
 }
 
+NS_IMETHODIMP
+GfxInfoBase::GetCodecSupportInfo(nsACString& aCodecSupportInfo) {
+  aCodecSupportInfo.Assign(gfx::gfxVars::CodecSupportInfo());
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 GfxInfoBase::GetIsHeadless(bool* aIsHeadless) {
   *aIsHeadless = gfxPlatform::IsHeadless();

widget/GfxInfoBase.h

@@ -71,6 +71,7 @@ class GfxInfoBase : public nsIGfxInfo,
   NS_IMETHOD GetWebRenderEnabled(bool* aWebRenderEnabled) override;
   NS_IMETHOD GetIsHeadless(bool* aIsHeadless) override;
   NS_IMETHOD GetTargetFrameRate(uint32_t* aTargetFrameRate) override;
+  NS_IMETHOD GetCodecSupportInfo(nsACString& aCodecSupportInfo) override;
 
   // Non-XPCOM method to get IPC data:
   nsTArray<mozilla::gfx::GfxInfoFeatureStatus> GetAllFeatures();

widget/nsIGfxInfo.idl

@@ -37,6 +37,7 @@ interface nsIGfxInfo : nsISupports
   readonly attribute boolean WebRenderEnabled;
   readonly attribute boolean isHeadless;
   readonly attribute unsigned long TargetFrameRate;
+  readonly attribute ACString CodecSupportInfo;
 
   // XXX: Switch to a list of devices, rather than explicitly numbering them.