Add a flag to specify the amount of total GPU memory available.

content/common/gpu/gpu_memory_manager.h

Index: content/common/gpu/gpu_memory_manager.h
diff --git a/content/common/gpu/gpu_memory_manager.h b/content/common/gpu/gpu_memory_manager.h
index d3268cadb9b32520d372110d9dcf47fa05ae8739..5f65fbb099e0804ed7947c2d2dff7f50b598ce0b 100644
--- a/content/common/gpu/gpu_memory_manager.h
+++ b/content/common/gpu/gpu_memory_manager.h
@@ -42,22 +42,6 @@ class CONTENT_EXPORT GpuMemoryManager :
  public:
   enum { kDefaultMaxSurfacesWithFrontbufferSoftLimit = 8 };
 
-  // These are predefined values (in bytes) for
-  // GpuMemoryAllocation::gpuResourceSizeInBytes.
-  // Maximum Allocation for all tabs is a soft limit that can be exceeded
-  // during the time it takes for renderers to respect new allocations,
-  // including when switching tabs or opening a new window.
-  // To alleviate some pressure, we decrease our desired limit by "one tabs'
-  // worth" of memory.
-  enum {
-#if defined(OS_ANDROID)
-    kMinimumAllocationForTab = 32 * 1024 * 1024,
-    kMaximumAllocationForTabs = 64 * 1024 * 1024,
-#else
-    kMinimumAllocationForTab = 64 * 1024 * 1024,
-    kMaximumAllocationForTabs = 512 * 1024 * 1024 - kMinimumAllocationForTab,
-#endif
-  };
 
   // StubMemoryStat is used to store memory-allocation-related information about
   // a GpuCommandBufferStubBase for some time point.
@@ -88,19 +72,31 @@ class CONTENT_EXPORT GpuMemoryManager :
     return stub_memory_stats_for_last_manage_;
   }
 
-  // Tries to estimate the total available gpu memory for use by
-  // GpuMemoryManager.  Ideally should consider other system applications and
-  // other internal but non GpuMemoryManager managed sources, etc.
-  size_t GetAvailableGpuMemory() const;
-
   // Track a change in memory allocated by any context
   void TrackMemoryAllocatedChange(size_t old_size, size_t new_size);
 
-
  private:
   friend class GpuMemoryManagerTest;
+
   void Manage();
 
+#if defined(OS_ANDROID)
+  size_t CalculateBonusMemoryAllocationBasedOnSize(gfx::Size size) const;
+#endif
+
+  size_t GetAvailableGpuMemory() const {
+    return bytes_available_gpu_memory_;
+  }
+
+  // The minimum non-zero amount of memory that a tab may be assigned
+  size_t GetMinimumTabAllocation() const {
+#if defined(OS_ANDROID)
+    return 32 * 1024 * 1024;
+#else
+    return 64 * 1024 * 1024;
+#endif
+  }
+
   class CONTENT_EXPORT StubWithSurfaceComparator {
    public:
     bool operator()(GpuCommandBufferStubBase* lhs,
@@ -116,6 +112,9 @@ class CONTENT_EXPORT GpuMemoryManager :
 
   StubMemoryStatMap stub_memory_stats_for_last_manage_;
 
+  // The maximum amount of memory that may be allocated for GPU resources
+  size_t bytes_available_gpu_memory_;
+
   // The current total memory usage, and historical maximum memory usage
   size_t bytes_allocated_current_;
   size_t bytes_allocated_historical_max_;