aw: Add more trace events to drawing functions

android_webview/browser/browser_view_renderer.cc

 // Copyright 2014 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 "android_webview/browser/browser_view_renderer.h"
 
 #include "android_webview/browser/browser_view_renderer_client.h"
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event_argument.h"
@@ skipping 126 matching lines @@
 
 void BrowserViewRenderer::PrepareToDraw(const gfx::Vector2d& scroll,
                                         const gfx::Rect& global_visible_rect) {
   last_on_draw_scroll_offset_ = scroll;
   last_on_draw_global_visible_rect_ = global_visible_rect;
 }
 
 bool BrowserViewRenderer::OnDrawHardware() {
   TRACE_EVENT0("android_webview", "BrowserViewRenderer::OnDrawHardware");
   shared_renderer_state_.InitializeHardwareDrawIfNeededOnUI();
-  if (!compositor_)
+  if (!compositor_) {
+    TRACE_EVENT_INSTANT0("android_webview", "EarlyOut_NoCompositor",
+                         TRACE_EVENT_SCOPE_THREAD);
     return false;
+  }
 
   shared_renderer_state_.SetScrollOffsetOnUI(last_on_draw_scroll_offset_);
 
   if (!hardware_enabled_) {
+    TRACE_EVENT0("android_webview", "InitializeHwDraw");
     hardware_enabled_ = compositor_->InitializeHwDraw();
   }
-  if (!hardware_enabled_)
+  if (!hardware_enabled_) {
+    TRACE_EVENT_INSTANT0("android_webview", "EarlyOut_HardwareNotEnabled",
+                         TRACE_EVENT_SCOPE_THREAD);
     return false;
+  }
 
   if (last_on_draw_global_visible_rect_.IsEmpty() &&
       parent_draw_constraints_.surface_rect.IsEmpty()) {
     TRACE_EVENT_INSTANT0("android_webview",
                          "EarlyOut_EmptyVisibleRect",
                          TRACE_EVENT_SCOPE_THREAD);
     shared_renderer_state_.SetForceInvalidateOnNextDrawGLOnUI(true);
     return true;
   }
 
   ReturnResourceFromParent();
   if (shared_renderer_state_.HasCompositorFrameOnUI()) {
     TRACE_EVENT_INSTANT0("android_webview",
                          "EarlyOut_PreviousFrameUnconsumed",
                          TRACE_EVENT_SCOPE_THREAD);
     DidSkipCompositeInDraw();
     return true;
   }
 
   scoped_ptr<cc::CompositorFrame> frame = CompositeHw();
-  if (!frame.get())
+  if (!frame.get()) {
+    TRACE_EVENT_INSTANT0("android_webview", "NoNewFrame",
+                         TRACE_EVENT_SCOPE_THREAD);
     return false;
+  }
 
   shared_renderer_state_.SetCompositorFrameOnUI(frame.Pass(), false);
   return true;
 }
 
 scoped_ptr<cc::CompositorFrame> BrowserViewRenderer::CompositeHw() {
   compositor_->SetMemoryPolicy(CalculateDesiredMemoryPolicy());
 
   parent_draw_constraints_ =
       shared_renderer_state_.GetParentDrawConstraintsOnUI();
@@ skipping 533 matching lines @@
   base::StringAppendF(&str,
                       "overscroll_rounding_error_: %s ",
                       overscroll_rounding_error_.ToString().c_str());
   base::StringAppendF(
       &str, "on_new_picture_enable: %d ", on_new_picture_enable_);
   base::StringAppendF(&str, "clear_view: %d ", clear_view_);
   return str;
 }
 
 }  // namespace android_webview