Bug 815671 part 6. Fixes to widget code to not copy arrays implicitly. r=jlebar

widget/android/AndroidJavaWrappers.h

@@ -655,11 +655,11 @@ public:
     int Action() { return mAction; }
     int Type() { return mType; }
     int64_t Time() { return mTime; }
-    nsTArray<nsIntPoint> Points() { return mPoints; }
-    nsTArray<int> PointIndicies() { return mPointIndicies; }
-    nsTArray<float> Pressures() { return mPressures; }
-    nsTArray<float> Orientations() { return mOrientations; }
-    nsTArray<nsIntPoint> PointRadii() { return mPointRadii; }
+    const nsTArray<nsIntPoint>& Points() { return mPoints; }
+    const nsTArray<int>& PointIndicies() { return mPointIndicies; }
+    const nsTArray<float>& Pressures() { return mPressures; }
+    const nsTArray<float>& Orientations() { return mOrientations; }
+    const nsTArray<nsIntPoint>& PointRadii() { return mPointRadii; }
     double X() { return mX; }
     double Y() { return mY; }
     double Z() { return mZ; }

widget/android/nsAppShell.cpp

@@ -71,7 +71,9 @@ NS_IMPL_ISUPPORTS_INHERITED1(nsAppShell, nsBaseAppShell, nsIObserver)
 
 class ScreenshotRunnable : public nsRunnable {
 public:
-    ScreenshotRunnable(nsIAndroidBrowserApp* aBrowserApp, int aTabId, nsTArray<nsIntPoint>& aPoints, int aToken, RefCountedJavaObject* aBuffer):
+    ScreenshotRunnable(nsIAndroidBrowserApp* aBrowserApp, int aTabId,
+                       const nsTArray<nsIntPoint>& aPoints, int aToken,
+                       RefCountedJavaObject* aBuffer):
         mBrowserApp(aBrowserApp), mPoints(aPoints), mTabId(aTabId), mToken(aToken), mBuffer(aBuffer) {}
 
     virtual nsresult Run() {
@@ -506,7 +508,7 @@ nsAppShell::ProcessNextNativeEvent(bool mayWait)
 
         int32_t token = curEvent->Flags();
         int32_t tabId = curEvent->MetaState();
-        nsTArray<nsIntPoint> points = curEvent->Points();
+        const nsTArray<nsIntPoint>& points = curEvent->Points();
         RefCountedJavaObject* buffer = curEvent->ByteBuffer();
         nsCOMPtr<ScreenshotRunnable> sr = 
             new ScreenshotRunnable(mBrowserApp, tabId, points, token, buffer);

widget/android/nsWindow.cpp

@@ -757,7 +757,7 @@ nsWindow::OnGlobalAndroidEvent(AndroidGeckoEvent *ae)
                 win->mChildren[i]->mBounds.height = 0;
             }
         case AndroidGeckoEvent::SIZE_CHANGED: {
-            nsTArray<nsIntPoint> points = ae->Points();
+            const nsTArray<nsIntPoint>& points = ae->Points();
             NS_ASSERTION(points.Length() == 2, "Size changed does not have enough coordinates");
 
             int nw = points[0].x;
@@ -827,7 +827,7 @@ nsWindow::OnGlobalAndroidEvent(AndroidGeckoEvent *ae)
             win->UserActivity();
             if (!gTopLevelWindows.IsEmpty()) {
                 nsIntPoint pt(0,0);
-                nsTArray<nsIntPoint> points = ae->Points();
+                const nsTArray<nsIntPoint>& points = ae->Points();
                 if (points.Length() > 0) {
                     pt = points[0];
                 }
@@ -852,7 +852,7 @@ nsWindow::OnGlobalAndroidEvent(AndroidGeckoEvent *ae)
 
         case AndroidGeckoEvent::NATIVE_GESTURE_EVENT: {
             nsIntPoint pt(0,0);
-            nsTArray<nsIntPoint> points = ae->Points();
+            const nsTArray<nsIntPoint>& points = ae->Points();
             if (points.Length() > 0) {
                 pt = points[0];
             }

widget/windows/nsWindow.cpp

@@ -6982,15 +6982,13 @@ CreateHRGNFromArray(const nsTArray<nsIntRect>& aRects)
   return ::ExtCreateRegion(NULL, buf.Length(), data);
 }
 
-static const nsTArray<nsIntRect>
-ArrayFromRegion(const nsIntRegion& aRegion)
+static void
+ArrayFromRegion(const nsIntRegion& aRegion, nsTArray<nsIntRect>& aRects)
 {
-  nsTArray<nsIntRect> rects;
   const nsIntRect* r;
   for (nsIntRegionRectIterator iter(aRegion); (r = iter.Next());) {
-    rects.AppendElement(*r);
+    aRects.AppendElement(*r);
   }
-  return rects;
 }
 
 nsresult
@@ -7020,7 +7018,8 @@ nsWindow::SetWindowClipRegion(const nsTArray<nsIntRect>& aRects,
     nsIntRegion intersection;
     intersection.And(currentRegion, newRegion);
     // create int rect array from intersection
-    nsTArray<nsIntRect> rects = ArrayFromRegion(intersection);
+    nsTArray<nsIntRect> rects;
+    ArrayFromRegion(intersection, rects);
     // store
     if (!StoreWindowClipRegion(rects))
       return NS_OK;