Fix UpdateTilePriorities viewport in Android WebView.

content/browser/android/in_process/synchronous_compositor_output_surface.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/android/in_process/synchronous_compositor_output_surface.h"
 
 #include "base/auto_reset.h"
 #include "base/logging.h"
 #include "cc/output/begin_frame_args.h"
 #include "cc/output/compositor_frame.h"
@@ skipping 168 matching lines @@
   }
   SynchronousCompositorOutputSurfaceDelegate* delegate = GetDelegate();
   if (delegate)
     delegate->UpdateFrameMetaData(frame->metadata);
 
   did_swap_buffer_ = true;
   DidSwapBuffers();
 }
 
 namespace {
-void AdjustTransformForClip(gfx::Transform* transform, gfx::Rect clip) {
-  // The system-provided transform translates us from the screen origin to the
-  // origin of the clip rect, but CC's draw origin starts at the clip.
-  transform->matrix().postTranslate(-clip.x(), -clip.y(), 0);
+void AdjustTransform(gfx::Transform* transform, gfx::Rect viewport) {
+  // CC's draw origin starts at the viewport.
+  transform->matrix().postTranslate(-viewport.x(), -viewport.y(), 0);
 }
 } // namespace
 
 bool SynchronousCompositorOutputSurface::InitializeHwDraw(
     scoped_refptr<gfx::GLSurface> surface,
     scoped_refptr<cc::ContextProvider> offscreen_context_provider) {
   DCHECK(CalledOnValidThread());
   DCHECK(HasClient());
   DCHECK(!context_provider_);
   DCHECK(surface);
 
   scoped_refptr<cc::ContextProvider> onscreen_context_provider =
       webkit::gpu::ContextProviderInProcess::Create(
           CreateWebGraphicsContext3D(surface));
   return InitializeAndSetContext3d(onscreen_context_provider,
                                    offscreen_context_provider);
 }
 
 void SynchronousCompositorOutputSurface::ReleaseHwDraw() {
   cc::OutputSurface::ReleaseGL();
 }
 
 bool SynchronousCompositorOutputSurface::DemandDrawHw(
     gfx::Size surface_size,
     const gfx::Transform& transform,
+    gfx::Rect viewport,
     gfx::Rect clip,
     bool stencil_enabled) {
   DCHECK(CalledOnValidThread());
   DCHECK(HasClient());
   DCHECK(context_provider_);
 
-  gfx::Transform adjusted_transform = transform;
-  AdjustTransformForClip(&adjusted_transform, clip);
   surface_size_ = surface_size;
-  SetExternalDrawConstraints(adjusted_transform, clip);
   SetExternalStencilTest(stencil_enabled);
-  InvokeComposite(clip.size());
+  InvokeComposite(transform, viewport, clip, true);
 
   return did_swap_buffer_;
 }
 
 bool SynchronousCompositorOutputSurface::DemandDrawSw(SkCanvas* canvas) {
   DCHECK(CalledOnValidThread());
   DCHECK(canvas);
   DCHECK(!current_sw_canvas_);
   base::AutoReset<SkCanvas*> canvas_resetter(&current_sw_canvas_, canvas);
 
   SkIRect canvas_clip;
   canvas->getClipDeviceBounds(&canvas_clip);
   gfx::Rect clip = gfx::SkIRectToRect(canvas_clip);
 
   gfx::Transform transform(gfx::Transform::kSkipInitialization);
   transform.matrix() = canvas->getTotalMatrix();  // Converts 3x3 matrix to 4x4.
-  AdjustTransformForClip(&transform, clip);
 
   surface_size_ = gfx::Size(canvas->getDeviceSize().width(),
                             canvas->getDeviceSize().height());
-  SetExternalDrawConstraints(transform, clip);
   SetExternalStencilTest(false);
 
-  InvokeComposite(clip.size());
+  InvokeComposite(transform, clip, clip, false);
 
   return did_swap_buffer_;
 }
 
 void SynchronousCompositorOutputSurface::InvokeComposite(
-    gfx::Size damage_size) {
+    const gfx::Transform& transform,
+    gfx::Rect viewport,
+    gfx::Rect clip,
+    bool valid_for_tile_management) {
   DCHECK(!invoking_composite_);
   base::AutoReset<bool> invoking_composite_resetter(&invoking_composite_, true);
   did_swap_buffer_ = false;
-  SetNeedsRedrawRect(gfx::Rect(damage_size));
+
+  gfx::Transform adjusted_transform = transform;
+  AdjustTransform(&adjusted_transform, viewport);
+  SetExternalDrawConstraints(
+      adjusted_transform, viewport, clip, valid_for_tile_management);
+  SetNeedsRedrawRect(gfx::Rect(viewport.size()));
+
   if (needs_begin_frame_)
     BeginFrame(cc::BeginFrameArgs::CreateForSynchronousCompositor());
 
+  // After software draws (which might move the viewport arbitrarily), restore
+  // the previous hardware viewport to allow CC's tile manager to prioritize
+  // properly.
+  if (valid_for_tile_management) {
+    cached_hw_transform_ = adjusted_transform;
+    cached_hw_viewport_ = viewport;
+    cached_hw_clip_ = clip;
+  } else {
+    SetExternalDrawConstraints(
+        cached_hw_transform_, cached_hw_viewport_, cached_hw_clip_, true);
+  }
+
   if (did_swap_buffer_)
     OnSwapBuffersComplete(NULL);
 }
 
 void SynchronousCompositorOutputSurface::PostCheckForRetroactiveBeginFrame() {
   // Synchronous compositor cannot perform retroactive begin frames, so
   // intentionally no-op here.
 }
 
 // Not using base::NonThreadSafe as we want to enforce a more exacting threading
 // requirement: SynchronousCompositorOutputSurface() must only be used on the UI
 // thread.
 bool SynchronousCompositorOutputSurface::CalledOnValidThread() const {
   return BrowserThread::CurrentlyOn(BrowserThread::UI);
 }
 
 SynchronousCompositorOutputSurfaceDelegate*
 SynchronousCompositorOutputSurface::GetDelegate() {
   return SynchronousCompositorImpl::FromRoutingID(routing_id_);
 }
 
 }  // namespace content