content: Add SharedBitmap MemoryDumpProvider implementation.

content/common/host_shared_bitmap_manager.h

Index: content/common/host_shared_bitmap_manager.h
diff --git a/content/common/host_shared_bitmap_manager.h b/content/common/host_shared_bitmap_manager.h
index ce95f76bb076bfb694f1e7f309a14e0ba40c057b..ab846fb668fe243bb25c0c55bc7768dff4a310c1 100644
--- a/content/common/host_shared_bitmap_manager.h
+++ b/content/common/host_shared_bitmap_manager.h
@@ -15,6 +15,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/shared_memory.h"
 #include "base/synchronization/lock.h"
+#include "base/trace_event/memory_dump_provider.h"
 #include "cc/resources/shared_bitmap_manager.h"
 #include "content/common/content_export.h"
 
@@ -55,7 +56,9 @@ class CONTENT_EXPORT HostSharedBitmapManagerClient {
   DISALLOW_COPY_AND_ASSIGN(HostSharedBitmapManagerClient);
 };
 
-class CONTENT_EXPORT HostSharedBitmapManager : public cc::SharedBitmapManager {
+class CONTENT_EXPORT HostSharedBitmapManager
+    : public cc::SharedBitmapManager,
+      public base::trace_event::MemoryDumpProvider {
  public:
   HostSharedBitmapManager();
   ~HostSharedBitmapManager() override;
@@ -69,6 +72,9 @@ class CONTENT_EXPORT HostSharedBitmapManager : public cc::SharedBitmapManager {
       const gfx::Size& size,
       const cc::SharedBitmapId&) override;
 
+  // base::trace_event::MemoryDumpProvider implementation.
+  bool OnMemoryDump(base::trace_event::ProcessMemoryDump* pmd) override;
+
   size_t AllocatedBitmapCount() const;
 
   void FreeSharedMemoryFromMap(const cc::SharedBitmapId& id);