Improve GPU process URL crash reporting

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 bf38bbda8b141f8d131e52d20ad1e23582018841..b3947b17a8e3f3b833f591944db6a7e229df795e 100644
--- a/content/common/gpu/gpu_command_buffer_stub.cc
+++ b/content/common/gpu/gpu_command_buffer_stub.cc
@@ -20,6 +20,7 @@
 #include "content/common/gpu/image_transport_surface.h"
 #include "content/common/gpu/media/gpu_video_decode_accelerator.h"
 #include "content/common/gpu/sync_point_manager.h"
+#include "content/public/common/content_client.h"
 #include "gpu/command_buffer/common/constants.h"
 #include "gpu/command_buffer/common/gles2_cmd_utils.h"
 #include "ui/gl/gl_bindings.h"
@@ -29,6 +30,22 @@
 #include "content/public/common/sandbox_init.h"
 #endif
 
+namespace {
+
+// FastSetActiveURL will shortcut the expensive call to SetActiveURL when the
+// url_hash matches.

[Ken Russell (switch to Gerrit), 2012/07/10 23:38:01]

Any indication of what kind of speedup this yields? Would it be better to just
optimize the implementation of ContentClient::SetActiveURL()?

[jbates, 2012/07/11 00:07:18]

From a quick printf run, the majority of FastSetActiveURL calls had a matching
hash, so it's definitely a speedup but I'm not sure how much. Since URLs can be
very long, even a perfect implementation of ContentClient::SetActiveURL(url)
would require a O(n) memcpy or strcmp for every call.
ContentClient::SetActiveURL could be refactored to take a hash, but the other
use cases that I found are not as high frequency as GpuScheduler::PutChanged, so
it seemed appropriate to just implement this here. In the grand scheme of things
I doubt we'd ever notice, but I will sleep better if this optimization stays in
:)

+void FastSetActiveURL(const GURL& url, size_t url_hash) {
+  static GURL g_last_url;
+  static size_t g_last_url_hash;
+  if (url_hash != g_last_url_hash) {
+    g_last_url = url;
+    g_last_url_hash = url_hash;
+    content::GetContentClient()->SetActiveURL(url);
+  }
+}
+
+}
+
 GpuCommandBufferStub::SurfaceState::SurfaceState(int32 surface_id,
                                                  bool visible,
                                                  base::TimeTicks last_used_time)
@@ -50,7 +67,8 @@ GpuCommandBufferStub::GpuCommandBufferStub(
     int32 route_id,
     int32 surface_id,
     GpuWatchdog* watchdog,
-    bool software)
+    bool software,
+    const GURL& active_url)
     : channel_(channel),
       handle_(handle),
       initial_size_(size),
@@ -65,7 +83,10 @@ GpuCommandBufferStub::GpuCommandBufferStub(
       parent_stub_for_initialization_(),
       parent_texture_for_initialization_(0),
       watchdog_(watchdog),
-      sync_point_wait_count_(0) {
+      sync_point_wait_count_(0),
+      active_url_(active_url) {
+  active_url_hash_ =
+      base::hash<std::string>()(active_url.possibly_invalid_spec());
   if (share_group) {
     context_group_ = share_group->context_group_;
   } else {
@@ -345,8 +366,7 @@ void GpuCommandBufferStub::OnInitialize(
                  base::Unretained(this)));
 
   command_buffer_->SetPutOffsetChangeCallback(
-      base::Bind(&gpu::GpuScheduler::PutChanged,
-                 base::Unretained(scheduler_.get())));
+      base::Bind(&GpuCommandBufferStub::PutChanged, base::Unretained(this)));
   command_buffer_->SetGetBufferChangeCallback(
       base::Bind(&gpu::GpuScheduler::SetGetBuffer,
                  base::Unretained(scheduler_.get())));
@@ -582,6 +602,11 @@ void GpuCommandBufferStub::ReportState() {
   }
 }
 
+void GpuCommandBufferStub::PutChanged() {
+  FastSetActiveURL(active_url_, active_url_hash_);
+  scheduler_->PutChanged();
+}
+
 void GpuCommandBufferStub::OnCreateVideoDecoder(
     media::VideoCodecProfile profile,
     IPC::Message* reply_message) {