Revert of CompositorViewHolder is source of truth for viewports

chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java

Index: chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java b/chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java
index 86e046e8e68befe1b5724cffebb4c1d8ac95ba9f..4fab61f8e2a2e3e558ddc8d7a75ae0436bafe269 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java
@@ -118,6 +118,7 @@
 
     // Cache objects that should not be created frequently.
     private final RectF mCacheViewport = new RectF();
+    private final RectF mCacheVisibleViewport = new RectF();
     private DrawingInfo mProgressBarDrawingInfo;
 
     // If we've drawn at least one frame.
@@ -203,7 +204,7 @@
             @Override
             public void onLayoutChange(View v, int left, int top, int right, int bottom,
                     int oldLeft, int oldTop, int oldRight, int oldBottom) {
-                onViewportChanged();
+                propagateViewportToLayouts(right - left, bottom - top);
 
                 // If there's an event that needs to occur after the keyboard is hidden, post
                 // it as a delayed event.  Otherwise this happens in the midst of the
@@ -229,7 +230,7 @@
      */
     public void setLayoutManager(LayoutManager layoutManager) {
         mLayoutManager = layoutManager;
-        onViewportChanged();
+        propagateViewportToLayouts(getWidth(), getHeight());
     }
 
     /**
@@ -452,13 +453,13 @@
     @Override
     public void onContentOffsetChanged(float offset) {
         mLastContentOffset = offset;
-        onViewportChanged();
+        propagateViewportToLayouts(getWidth(), getHeight());
     }
 
     @Override
     public void onVisibleContentOffsetChanged(float offset, boolean needsAnimate) {
         mLastVisibleContentOffset = offset;
-        onViewportChanged();
+        propagateViewportToLayouts(getWidth(), getHeight());
         if (needsAnimate) requestRender();
     }
 
@@ -493,12 +494,27 @@
         }
     }
 
-    private void onViewportChanged() {
+    private void propagateViewportToLayouts(int contentWidth, int contentHeight) {
+        int heightMinusBrowserControls = contentHeight
+                - (getTopControlsHeightPixels() + getBottomControlsHeightPixels());
+        int bottomControlOffset = mFullscreenManager != null
+                ? (int) mFullscreenManager.getBottomControlOffset() : 0;
+        int viewportBottom =
+                contentHeight - (getBottomControlsHeightPixels() - bottomControlOffset);
+
+        // The only time that mCacheViewport and mCacheVisibleViewport are different is when the
+        // browser has manipulated the browser controls offset.
+        mCacheViewport.set(0, (int) mLastContentOffset, contentWidth, viewportBottom);
+        mCacheVisibleViewport.set(0, (int) mLastVisibleContentOffset, contentWidth, viewportBottom);
         // TODO(changwan): check if this can be merged with setContentMotionEventOffsets.
         if (mTabVisible != null && mTabVisible.getContentViewCore() != null) {
-            mTabVisible.getContentViewCore().setSmartClipOffsets(0, (int) -mLastContentOffset);
-        }
-        if (mLayoutManager != null) mLayoutManager.onViewportChanged();
+            mTabVisible.getContentViewCore().setSmartClipOffsets(
+                    (int) -mCacheViewport.left, (int) -mCacheViewport.top);
+        }
+        if (mLayoutManager != null) {
+            mLayoutManager.pushNewViewport(
+                    mCacheViewport, mCacheVisibleViewport, heightMinusBrowserControls);
+        }
     }
 
     /**
@@ -522,32 +538,6 @@
         }
 
         TraceEvent.end("CompositorViewHolder:layout");
-    }
-
-    @Override
-    public void getWindowViewport(RectF outRect) {
-        outRect.set(0, 0, getWidth(), getHeight());
-    }
-
-    @Override
-    public void getVisibleViewport(RectF outRect) {
-        // All of these values are in pixels.
-        float viewportTop = 0;
-        float bottomControlOffset = 0;
-        if (mFullscreenManager != null) {
-            viewportTop = mFullscreenManager.getTopVisibleContentOffset();
-            bottomControlOffset = mFullscreenManager.getBottomControlOffset();
-        }
-        float viewportBottom =
-                getHeight() - (getBottomControlsHeightPixels() - bottomControlOffset);
-
-        outRect.set(0, viewportTop, getWidth(), viewportBottom);
-    }
-
-    @Override
-    public float getHeightMinusBrowserControls() {
-        return getHeight() - (getTopControlsHeightPixels() + getBottomControlsHeightPixels());
-
     }
 
     @Override
@@ -624,7 +614,7 @@
     @Override
     protected void onLayout(boolean changed, int l, int t, int r, int b) {
         if (changed) {
-            onViewportChanged();
+            propagateViewportToLayouts(r - l, b - t);
         }
         super.onLayout(changed, l, t, r, b);
 
@@ -654,7 +644,7 @@
             mLastVisibleContentOffset = mFullscreenManager.getTopVisibleContentOffset();
             mFullscreenManager.addListener(this);
         }
-        onViewportChanged();
+        propagateViewportToLayouts(getWidth(), getHeight());
     }
 
     @Override
@@ -691,7 +681,7 @@
     public float getOverlayTranslateY() {
         return areBrowserControlsPermanentlyHidden()
                 ? getTopControlsHeightPixels()
-                : mLastVisibleContentOffset;
+                : mCacheVisibleViewport.top;
     }
 
     /**