GpuMemoryManager should limit memory allocations based on viewport size for android.

content/common/gpu/gpu_command_buffer_stub.cc

Index: content/common/gpu/gpu_command_buffer_stub.cc
diff --git a/content/common/gpu/gpu_command_buffer_stub.cc b/content/common/gpu/gpu_command_buffer_stub.cc
index 41fa5e5a2ffd6158f1b6e13370cc69f961b1f879..a5f95a7dccc55239d7a884208bf99cb38e80f110 100644
--- a/content/common/gpu/gpu_command_buffer_stub.cc
+++ b/content/common/gpu/gpu_command_buffer_stub.cc
@@ -622,6 +622,12 @@ void GpuCommandBufferStub::RemoveDestructionObserver(
   destruction_observers_.RemoveObserver(observer);
 }
 
+gfx::Size GpuCommandBufferStub::GetSurfaceSize() const {
+  if (!surface_)
+    return gfx::Size();
+  return surface_->GetSize();
+}
+
 bool GpuCommandBufferStub::IsInSameContextShareGroup(
     const GpuCommandBufferStubBase& other) const {
   return context_group_ ==